M. ebrahimi - Sadjad University of Technology mashhad,iran
E. salimi - Sadjad University of Technology mashhad,iran
M. rajabi mashhadi - Khorasan Regional Electric Company, Sadjad University of Technology mashhad,iran

During recent years due to the policymaking at the international level as well as the policies adopted by the Ministry of Energy of Iran at the domestic level, the use of small photovoltaic generators has received priority by the household subscriber. Because such generators show non-linear behavior resulting from uncertainty of the sunlight radiation, designing and employing active filters for them seems necessary. Accordingly, a single-phase parallel active filter has been designed for compensating the current and voltage harmonics of a photovoltaic system. The filter has been engineered through indirect method and for the adjustment of reference flow amplitude -that regulates the DC capacitor's voltage- a PI controller has been used. Also for controlling the output current of the parallel active filter with the lowest ripple, the hysteresis band current controller has been employed. In order to obtain a sinusoidal wave with reasonable THD, a passive low-pass filter has been used. Finally, the effects of the explained control pattern for the single-phase active filter and the photovoltaic system have been simulated using Matlab/Simulink software. Results from the simulation show that both voltage and current harmonics' values have considerably been improved and in some cases have been decreased about 80 percent.

Photovoltaic System; Active and passive filters; Voltage and current harmonics